Clean Technology (청정기술)

The Korean Society of Clean Technology (한국청정기술학회)
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Recycling Organic Sludge into Modification Block by Hydrothermal Carbonization (HTC)

열수가압탄화공법을 적용한 유기성 슬러지의 응용 블록 제조에 관한 연구

  • Hyewon Park (School of Environmental Engineering, University of Seoul) ;
  • Minah Oh (School of Environmental Engineering, University of Seoul) ;
  • Seungjin Oh (School of Environmental Engineering, University of Seoul) ;
  • Woori Cho (School of Environmental Engineering, University of Seoul) ;
  • Jinman Chang (School of Environmental Engineering, University of Seoul) ;
  • Jai-young Lee (School of Environmental Engineering, University of Seoul)
  • 박혜원 (서울시립대학교 환경공학부) ;
  • 오민아 (서울시립대학교 환경공학부) ;
  • 오승진 (서울시립대학교 환경공학부) ;
  • 조우리 (서울시립대학교 환경공학부) ;
  • 장진만 (서울시립대학교 환경공학부) ;
  • 이재영 (서울시립대학교 환경공학부)
  • Received : 2023.05.08
  • Accepted : 2023.05.26
  • Published : 2023.06.30
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Abstract

This study applied a hydrothermal carbonization (HTC) method to carbonize sewage sludge in order to satisfy the criteria of the Waste Management Act for recycled products and to explore the possibility of recycling sludge into modification blocks. Cement was mixed with carbonized sludge generated at the optimal temperature and reaction time during HTC. After that, the compressive strengths of the modification blocks were measured by conducting both a performance and leaching test. The results of the leaching test showed that heavy metals were not detected, and the specific gravity and absorption rates were less than 1.7 and 10%, respectively, indicating that all species satisfied the criteria. The results of the compressive strength test showed that a mixing ratio of 5% and 7% with cement cured for 28 days satisfied the criteria of A, B, and C type blocks but a mixing ratio of 3% with cement did not satisfy the criteria of A type blocks after 28 days. However, after additional curing for 42 days, the mixing ratio of 3% also satisfied the A type block criteria. Therefore, the optimal mixing ratio of carbonized sludge and cement was considered to be between 3% and 5% and confirmed that the modified blocks could be utilized as aggregates.

본 연구는 열수가압탄화공법(HTC)을 적용하여 하수슬러지를 탄화시켜 폐기물관리법에 따른 재활용 제품 기준을 만족하고, 응용 블록으로서의 재활용 가능성을 판단하였다. HTC 최적 반응온도와 시간을 통해 생성된 탄화 슬러지에 시멘트를 배합비 별로 배합하여 응용 블록의 공시체를 제작하였고, 중금속 용출 가능성과 성능분석을 진행하였다. 실험 결과 모든 응용 블록에서 중금속이 검출되지 않았으며, 성능분석의 비중과 흡수율의 경우 1.7 미만, 10% 이하의 해당 기준치를 만족하였다. 압축강도의 경우 28일 재령 기준으로 시멘트 5%, 7%의 배합비 경우 A, B, C종 블록 기준치에 만족하였으나, 시멘트 3%의 배합비 경우 A type 블록 기준에 미치지 못하였다. 이후 추가적인 재령을 진행한 결과 42일 차 재령 강도에서 A종 블록 기준을 만족하였다. 따라서 본 연구의 탄화 슬러지와 시멘트의 최적 배합비는 3% 이상 5% 이내로 판단하였으며 향후 응용 블록을 골재로서의 재활용 가능성을 확인하였다.

Keywords

Acknowledgement

본 연구는 환경부 "폐자원에너지화 재활용 전문인력 양성사업(YL-WE-22-001)"에서 지원받았으며 이에 감사드립니다.

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